Question

A horse pulls a cart of mass 20 kg up a hill that has an incline of 26 degrees with the horizontal. It takes the horse 30 seconds to move the cart 300 m up the hill. Neglecting friction, determine: (a) the work done by the horse; (b) the power output of the horse.

Answer 1

My question is, do we only regard the force of gravity (mg) since the work of the normal force is perpendicular to displacement? (N = 0 joules). The force of the horse is not given.

Answer 2

First work out the force by the horse using Newton's laws, then you will be able to work out its work and power.

Answer 3

Do we find the x - component of mg vector? (mg sin theta) <--- is this the force of the horse? thanks

Answer 4

Yes it is!
force of traction is mg sin θ, up the plane.

Answer 5

What's the work done by the gravitational force? -mgh=-mglsin θ, therefore the work of the horse must be mglsin θ. For the power just divide by delta t